ZnO nanoparticles combined radio frequency heating: A novel method to control microorganism and improve product quality of prepared carrots

Abstract

Abstract Effects of ZnO nanoparticles combined radio frequency (RF) heating on the sterilization and product quality attributes (hardness, color, carotenoids and microstructure) of prepared carrots were investigated comparing to ZnO nanoparticles or RF heating treatment alone. The results showed that the combined sterilization effect of ZnO nanoparticles with radio frequency treatments was superior to ZnO nanoparticles or RF heating treatment alone and extended the shelf life of prepared carrots up to 60 days. ZnO nanoparticles combining RF heating 20 mm/20 min (plate spacing/RF heating time) reduced the loss of hardness, color difference value (ΔE), and carotenoids of prepared carrots. The Scanning electron micrographs (SEM) showed that the cell microstructure of prepared carrots that treated by RF treatments within 20 min was most closely integrated with each other. Therefore, the experimental results of ZnO nanoparticles combined with radio frequency heating could be helpful for food processing industries to produce high quality sterilized prepared carrots. Industrial relevance ZnO nanoparticles combined with radio frequency heating achieved logarithmic reduction of bacterial population and met China's national standard while preserving the color, texture and nutrition better. This information can be helpful for food processing industries to produce high quality sterilized prepared carrots and this same approach can be applied to many other prepared food formulations.